LC Lens Naked-Eye Stereoscopic Display is a mainstream technique in the current stereoscopic display field. Birefringent grating is a major component of the elements for achieving this technique. Its basic structure is shown in FIG. 1 and comprises the following parts: an optical resin substrate 1, an optical transparent layer 2 having concave lens structure, and a liquid crystal lens layer 3. Working under ideal 2D state, as shown in FIG. 2, when the polarized light emitted from under is perpendicular to the orientation of liquid crystals in the liquid crystal lens layer, the effective refractive index will present the extraordinary refractive index of the liquid crystal. Since the refractive index of the material in the optical transparent layer having concave lens structure, i.e., nx′ is identical to the ordinary refractive index of the liquid crystal lens layer, the refraction of light at the surface of the liquid crystal lens will then be offset, and the final image observed by the user will be the two dimensional image with the original resolution. However, in real 2D working conditions, as shown in FIG. 3, due to influence of many process conditions, the liquid crystal in the liquid crystal lens layer will not always be oriented optimally. In this case, the effective refractive index of the liquid crystal lens layer, i.e., ne′, is not always identical to the ordinary refractive index of the liquid crystal, and a certain deviation will occur, which will cause the mismatch between the refractive indices of the optical transparent layer and the liquid crystal lens layer, resulting in refraction at the curved surface of the lens, that is, there exists residual lens effect. In this case, the displayed 2D image will be observed with some dark bands or shadowed lines, which will severely affect the visual effect under 2D conditions.